package cn.efunbox.afw.core.security;

import java.security.DigestException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.*;

/**
 * Created by tomas on 2017/5/23.
 */
public class Sha1Signature {
    private static final String secret="U6$Ttz^bdRcwT+NA3s11OD@p";
    /**
     * SHA1 安全加密算法
     * @param maps 参数key-value map集合
     * @return
     * @throws DigestException
     */
    public static String sign(Map<String,Object> maps) throws DigestException {
        maps.put("secret",secret);
        //获取信息摘要 - 参数字典排序后字符串
        String decrypt = getOrderByLexicographic(maps);
        try {
            //指定sha1算法
            MessageDigest digest = MessageDigest.getInstance("SHA-1");
            digest.update(decrypt.getBytes());
            //获取字节数组
            byte messageDigest[] = digest.digest();
            // Create Hex String
            StringBuffer hexString = new StringBuffer();
            // 字节数组转换为 十六进制 数
            for (int i = 0; i < messageDigest.length; i++) {
                String shaHex = Integer.toHexString(messageDigest[i] & 0xFF);
                if (shaHex.length() < 2) {
                    hexString.append(0);
                }
                hexString.append(shaHex);
            }
            return hexString.toString().toUpperCase();

        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
            throw new DigestException("签名错误！");
        }
    }
    /**
     * 获取参数的字典排序
     * @param maps 参数key-value map集合
     * @return String 排序后的字符串
     */
    private static String getOrderByLexicographic(Map<String,Object> maps){
        return splitParams(lexicographicOrder(getParamsName(maps)),maps);
    }
    /**
     * 获取参数名称 key
     * @param maps 参数key-value map集合
     * @return
     */
    private static List<String> getParamsName(Map<String,Object> maps){
        List<String> paramNames = new ArrayList<String>();
        for(Map.Entry<String,Object> entry : maps.entrySet()){
            paramNames.add(entry.getKey());
        }
        return paramNames;
    }
    /**
     * 参数名称按字典排序
     * @param paramNames 参数名称List集合
     * @return 排序后的参数名称List集合
     */
    private static List<String> lexicographicOrder(List<String> paramNames){
        Collections.sort(paramNames);
        return paramNames;
    }
    /**
     * 拼接排序好的参数名称和参数值
     * @param paramNames 排序后的参数名称集合
     * @param maps 参数key-value map集合
     * @return String 拼接后的字符串
     */
    private static String splitParams(List<String> paramNames,Map<String,Object> maps){
        StringBuilder paramStr = new StringBuilder();
        for(String paramName : paramNames){
            paramStr.append(paramName);
            for(Map.Entry<String,Object> entry : maps.entrySet()){
                if(paramName.equals(entry.getKey())){
                    paramStr.append(String.valueOf(entry.getValue()));
                }
            }
        }
        System.out.println(paramStr.toString());
        return paramStr.toString();
    }

    public static void main(String[] args) throws Exception {
        Map<String,Object> map=new HashMap<>();
        map.put("appKey","2582535051");
        map.put("identityType","1");
        map.put("identityValue","440901197709194316");
        map.put("month","201601");
        //map.put("secret","B6F74A83BACF97D5AC24AE6573A4C8AA703F98D9");

        System.out.println(Sha1Signature.sign(map));
    }
}
